The present invention relates generally to the delivery of agents for medical treatment or diagnosis and, more particularly, to the delivery of such agents to the female reproductive tract.
A variety of delivery devices has been developed for the delivery of anesthetics, drugs, irrigation fluids, imaging contrast agents, and other agents to the body. Delivery of such agents can be accomplished either systemically or locally. Systemic delivery generally refers to delivery of agents to the body as a whole. Agents delivered systemically tend to travel to many different areas of the body. Localized delivery generally refers to delivery of agents to a particular area of the body, i.e., on a more targeted basis. There are many methods and techniques for delivering agents to body tissue systemically or locally. Existing techniques include, for example, oral administration, direct injection into body tissue, topical or transcutaneous administration, and intravenous administration.
Systemic delivery has a number of disadvantages. When drugs are systemically administered at high levels, for example, healthy tissue can be harmed, causing serious side effects in some cases. Also, drugs and contrast agents can be expensive, making the delivery of limited dosages more desirable. Systemic delivery may require a higher dosage, however, to achieve a desired level of the agent at the intended site. As a result, a portion of the agent can be wasted, driving up the cost of the treatment or diagnostic procedure. The high cost of pharmaceuticals, contrast agents, and the like makes minimization of waste a significant concern.
The disadvantages of systemic delivery make localized delivery desirable for many applications. One technique for localized delivery is to inject the agent directly into target tissue. Unfortunately, injection requires penetration by a needle or similar device, which is intrusive, painful, and often inaccurate. Moreover, injection may not evenly distribute the agent throughout the target area. To aggravate this situation, several injections may be required for relatively large target areas. Also, injection can produce a high concentration of the agent at the site of the injection, creating a large concentration gradient. Large concentrations are more likely to introduce significant quantities of the agent into the patient""s system, undermining the objective of localized delivery.
Transcutaneous delivery is another technique for localized delivery of agents to the body. Transcutaneous delivery systems generally are limited, however, to the application of an agent through the patient""s skin or other surface tissue. As a result, transcutaneous delivery of an agent to a target area that is large or situated deep within the patient""s body can be difficult. An example of a difficult target area for transcutaneous delivery is cervical and uterine tissue. Typically, a quantity of agent much larger than the amount required at the target site must be applied, resulting in waste and added expense.
The present invention provides a device for localized delivery of an agent to cervical and/or uterine tissue. The delivery device may include a number of features that aid in reducing leakage of the agent, and thereby improve the efficiency of the device. With more efficient delivery, the device is capable of improving diagnostic or therapeutic effectiveness and reducing waste and expense. In addition, the delivery device can make use of features that facilitate positioning relative to the cervix and cervical fixation without the need for a tenaculum or other painful manipulation devices.
The device may include a seal member that is configured to engage an outer surface of the cervix. Upon engagement with the outer surface of the cervix, the seal member defines a chamber. The seal member further defines a vacuum port and an agent delivery port, both of which are in fluid communication with the chamber.
The seal member can be mounted about an elongated member. The elongated member may take the form of a cannula having a distal end mounted at the agent delivery port. The cannula includes an inner lumen for introduction of an agent delivery catheter through the agent delivery port and into the cervical canal. As an alternative to use of a mounted cannula, a catheter may be introduced directly into the agent delivery port, e.g., via a catheter fitting such as a grommet. The catheter can be guided to the os of the cervical canal for delivery of the agent to the uterus.
The seal member, or a portion thereof, can be made from a compliant material that permits substantial deformation. For example, the seal member can be equipped with a compliant skirt-like member that contacts the outer surface of the cervix. Upon application of vacuum pressure via the vacuum port, at least a portion of the seal member, e.g., the skirt-like member, deforms and substantially seals the outer surface of the cervix against leakage of the agent. In this manner, fluid delivered to the cervix via the agent delivery catheter is substantially retained within the chamber, and more effectively transmitted to the cervix.
The use of vacuum pressure in combination with compliant characteristics of the seal member also facilitate positioning of the device relative to the cervix. In particular, the device permits a firm grasp of the cervix without significant trauma or discomfort. Thus, manipulation of the cervix can be less painful relative to other techniques such as the use of a tenaculum. At the same time, the device can facilitate catheter alignment and insertion for delivery of the desired agent or agents.
The seal member may include inner and outer walls that subdivide the chamber into an outer, annular chamber and an inner, central chamber, which are substantially concentric with one another. In this case, the vacuum port is in fluid communication with the annular chamber, whereas the agent delivery port is in fluid communication with the central chamber. Upon application of vacuum pressure, the inner and outer walls engage the outer surface of the cervix, and serve to separate the annular and central chambers from one another.
In this manner, fluid communication between the vacuum port and the central chamber is substantially avoided, preventing aspiration of the agent delivered via the central chamber by the vacuum port. A plug member that protrudes into the chamber can be further incorporated in the seal member. A catheter can be guided through the plug member. The plug member can be oriented for introduction into the os of the cervical canal, providing an added seal against leakage of agent delivered by the catheter.
Examples of agents that can be delivered using a device in accordance with the present invention include pharmaceutical agents, biological agents, cytotoxic agents, chemotherapeutic agents, hormones, radiotherapeutic agents, anesthetic agents, dyes such as methylene blue, imaging contrast agents, and irrigation fluids. Delivery of such agents using a device constructed as described herein reduces leakage and the resulting costs associated with waste. By preventing significant leakage, the device permits delivery of more precise amounts of an agent in a targeted manner. Moreover, the device can increase and expedite the effectiveness of the agent.
Although the present invention will be described primarily in the context of the delivery of agents in the form of drugs, contrast agents, and the like, the delivery device can be used for the introduction of imaging or surgical devices into the female reproductive tract, i.e., the uterine cervix and uterus. For example, the seal member can be configured to permit introduction of a variety of rigid or flexible devices such as hysteroscopes for endoscopy or ablation procedures within the uterus or cervix. In this case, the agent delivery port can be referred to as an instrument introduction port. Again, the structure of the seal member in combination with the application of vacuum pressure can facilitate the positioning of such devices. Moreover, the delivery device can substantially prevent leakage of distension fluids or other agents used in the course of such procedures.
The present invention provides, in one embodiment, a device for delivery of an agent to the uterine cervix, the device comprising a seal member that defines a chamber upon engagement with the cervix, an agent delivery port in fluid communication with the chamber, and a vacuum port in fluid communication with the chamber, wherein at least a portion of the seal member is deformable in response to application of vacuum pressure via the vacuum port to thereby substantially seal the chamber against leakage of the agent.
In another embodiment, the present invention provides a method for delivering an agent to the uterine cavity, the method comprising inserting a catheter through the cervical canal and into the uterine cavity, engaging a seal member with an outer surface of the cervix to define a chamber, at least a portion of the seal member being compliant, wherein the catheter passes through the seal member, applying vacuum pressure to a vacuum port associated with the chamber such that at least a portion of the seal member deforms to substantially seal the chamber against leakage, and delivering the agent to the uterine cavity via the catheter.
In a further embodiment, the present invention provides a device for delivery of an agent to the uterine cervix, the device comprising a seal member that, upon engagement with the cervix, includes an outer wall and an inner wall that together define an annular chamber and a central chamber substantially concentric within the annular chamber, a vacuum port in fluid communication with the annular chamber, and an agent delivery port in fluid communication with the central chamber, the seal member substantially sealing the central chamber against leakage of the agent upon application of vacuum pressure via the vacuum port.
In an added embodiment, the present invention provides a method for delivery of an agent to the uterine cervix, the method comprising engaging a deformable seal member with the cervix to define a chamber, applying vacuum pressure to the chamber to substantially seal the chamber against leakage, and delivering the agent to the chamber via a port defined in the seal member.
In a further embodiment, the present invention provides a device for introduction of an instrument to a position proximate to the female reproductive tract, the device comprising a seal member that defines a chamber upon engagement with the uterine cervix, an introduction port in communication with the chamber, the introduction port defining an aperture for introduction of an instrument, and a vacuum port in communication with the chamber, wherein at least a portion of the seal member is deformable in response to application of vacuum pressure via the vacuum port to thereby substantially seal the chamber.
In another embodiment, the present invention provides a method for introduction of an instrument to a position proximate to the female reproductive tract, the method comprising engaging a seal member with an outer surface of the uterine cervix to define a chamber, at least a portion of the seal member being compliant, the seal member defining an aperture, inserting an instrument through the aperture defined by the seal member, applying vacuum pressure to a vacuum port associated with the chamber such that at least a portion of the seal member deforms to substantially seal the chamber against leakage, and positioning a distal end of the instrument proximate to the female reproductive tract.
In an additional embodiment, the present invention provides a device for introduction of an instrument to a position proximate a portion of the female reproductive tract, the device comprising a seal member that, upon engagement with the uterine cervix, includes an outer wall and an inner wall that together define an annular chamber and a central chamber substantially concentric within the annular chamber, a vacuum port in fluid communication with the annular chamber, and an instrument introduction port in communication with the central chamber, the seal member substantially sealing the central chamber against the uterine cervix upon application of vacuum pressure via the vacuum port.
In yet another embodiment, the present invention provides a method for introduction of an instrument to a position proximate the female reproductive tract, the method comprising engaging a seal member with the uterine cervix to define a chamber, at least a portion of the seal member being deformable, wherein the seal member defines an aperture, applying vacuum pressure to the chamber to cause deformation of at least the portion of the seal member and substantially seal the chamber against the uterine cervix, introducing an instrument through the aperture defined by the seal member, and positioning a distal end of the instrument proximate to the female reproductive tract.